The present invention relates to strap devices for aiding human body muscles, and particularly to strap devices worn on a fully or partially paralyzed leg for assisting in hip, knee and foot movement of the wearer.
During an ambulatory cycle, each leg of an individual must come from the rearmost position it attains to a forward position, and then return to the rearmost position. For a stroke victim, or the like, who has lost all or partial control of a leg, moving the leg from the rearmost position of the ambulatory cycle to a forward position can be extremely difficult and unsaft. In addition, moving a leg back to the rearmost position requires putting weight on the leg for entire support of the body during at least a part of the cycle.
To safely move a paralyzed or partially paralyzed leg from the rearmost position of the ambulatory cycle to a forward position, it is necessary: (1) to hold the front of the foot up to prevent it from dragging or tripping the individual, (2) to bend the knee which also aids in keeping the front of the foot up, and (3) to hike the hip up to prevent the foot from dragging while it moves from the leg's rearmost position in the ambulatory cycle to a forward position. Once the front of the foot is held up, the knee bent, and the hip hiked up, a force must be applied which will pull the leg forward from the rearmost position of the ambulatory cycle. Finally, keeping the leg straight when moving the leg from a forward position to a rear position in the ambulatory cycle allows one to put weight on a fully or partially paralyzed leg without causing the leg to buckle.
Normally, the above functions are performed by various sets of muscles and tendons in the legs and hips of the human body. However, stroke victims and other paralyzed or partially paralyzed persons do not have normal use of such muscles. Thus, there is and has been a need for a strap device which can assist in the performance of entirely perform all of these functions.
In addition to performing the aforementioned functions, there is and has been a need for a strap device which assists in hip, knee and foot movement, and which is flexible enough that the wearer can use, and thus develop, his own muscles to the extent to which he is capable of using them. There is also a need for a strap device which assists in hip, knee and foot movement, which is capable of being worn under the clothes of the wearer to thus minimize the stigma which goes along with visual observation of such a device, and yet is adjustable and durable enough to fit and be used by persons of various sizes and weights.
There exists in the prior art a variety of strap devices used to perform specific functions with respect to the legs and feet of the wearer. None, however, perform or even assist in the performance of combined hip, knee and foot movements as in the present invention. For example, Dorsch, U.S. Pat. No. 2,004,487 discloses an elastic control strap 24 connecting a waist belt to an artificial leg, the apparent function of the elastic control strap being to swing the artificial leg in a forward direction from its rearmost position in the ambulatory cycle. U.S. Pat. Nos. to D. Bly 23,656 and Talati et al 3,923,045 disclose two structures designed to swing one's leg from its rearmost position in the ambulatory cycle to a more forward position. The Talati structure uses rigid supports. Combined control of knee extension, foot support and hip movement is not provided, especially for an existing, partially-functioning or wholly non-functioning human leg, by these prior devices. Two patents to J. J. Cooper, U.S. Pat. Nos. 1,548,711 and 1,562,294 disclose exercise-type strap devices disposed along the legs of the wearer which are designed to provide resistance to the muscles and tendons of the hips, legs and feet while walking in order to restore normal functions to defective muscles. Such devices appear to urge flexure of the knee and rearward movement of a leg opposite to the function provided by the present invention. Also, foot control is not contemplated. Finally, Ennis, U.S. Pat. No. 3,739,772 discloses a shoulder supported harness device for use with a walking cast designed to facilitate movement and reduce fatigue of the injured, cast-encased leg, and incorporates a shoulder strap, a lead strap, a resilient spring member, and a foot band. With this device, forward leg movement and knee extension are not controlled, especially in combination with foot control. Accordingly, the prior structures have not provided a device which can assist or provide the wearer with combined hip, knee and foot control as does the present invention.